The thiazolidine compounds which may be produced by the process of the invention described herein have the formula ##STR2## in which
R is halo, nitro, cyano, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, pentahalomethyl, difluoromethyl, pentafluoroethyl, trifluoromethylthio, difluoromethoxy, trifluoromethoxy, tetrafluoroethoxy, methylsulfonyl, C.sub.1 -C.sub.4 alkyloxyiminomethyl, benzyloxyiminomethyl, 1-(C.sub.1 -C.sub.4 alkyl)oxyiminoethyl or 1-benzyloxyiminoethyl;
R.sub.1 is hydrogen or halo;
R.sub.2 is hydrogen, C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 haloalkyl; and
R.sub.3 and R.sub.4 are independently hydrogen, halo, nitro, cyano, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 fluoroalkoxy or C.sub.1 -C.sub.4 alkylthio. These compounds are herbicidally active.